Masks are commonly used in a variety of situations where a user may have trouble breathing. These situations include supplying breathable gas in situations where the ambient level of breathable gas is low, such as in high altitude situations or fire fighting applications. Additionally, these masks may be used to treat a variety of ailments, for example obstructive sleep apnea. The masks typically cover the mouth and nose of a user and have an outer portion that contacts and seals against the face of the user. The delivery of breathable gas in the form of continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP) or variable airway pressure may then be administered to treat the condition of the user.
The masks are typically formed out of a solid material and can include a variety of ports or holes to allow for the delivery of breathable gas and the elimination of exhaust gas. The masks may also have formed on their bodies a variety of flanges or eyelets so as to allow for the fitment of straps, headgear or a harness to secure the mask to the face of a user. Additionally, the masks can utilize a cushion along their outside perimeter. The cushion typically acts to seal the mask against the face of a user, allowing for the proper delivery of input gas and preventing the delivered gas from escaping the mask. The cushion should also, however, be comfortable on the face of the wearer.
These masks often have a variety of problems, however. The masks are frequently formed in such a way that impinges on the comfort of the user. In an effort to create a gas-tight seal of the mask against the face of a wearer, uncomfortable cushions are utilized or the mask must be secured to the head of a wearer in such a fashion that impinges on comfort. Conversely, other masks utilize cushions that do not properly seal the mask against the face of a wearer or do not provide adequate means to secure the mask to the head of a wearer. Frequently the methods employed to secure the mask to the face of a wearer are uncomfortable and do not allow for adequate adjustments that allow a wearer to properly adjust and tailor the fitment of a mask so as to ensure the maximum sealing and comfort levels for that particular wearer. These problems are prominent when a primary purpose of the mask is that it is to be worn for long periods of time, for example, while a user sleeps. Masks that are uncomfortable can lead to a wearer not getting restful sleep, dislodging of the mask while a user sleeps or a user choosing not to wear the mask due to the level of discomfort. Masks that do not seal properly are unable to provide the desired treatment to a wearer.
The cushions on previous masks may also not be tailored to properly provide for sealing and comfort. Cushions are typically formed in a triangular shape, similar to the mask itself. This shape, however, is designed more to follow the contours of the mask rather than adhere to the contours of the face of a wearer. Previous masks also do not have adequate support for the chin of a wearer, which may lead to discomfort and improper sealing. Additionally, cushions used with previous masks have used two or more internal membranes the run throughout the internal perimeter of the cushion. These membranes, however, do not always properly adjust to the size and shape of the mask and therefore prevent proper sealing. Additionally, the use of multiple membranes throughout the internal perimeter of the cushion can distort other portions of the membrane, thereby preventing proper sealing of the cushion against the face of a wearer and impinging on the comfort of the wearer.
A variety of other types of ventilation devices exist that attempt to deliver breathable gas to a wearer while maintaining a seal against the face of a wearer while maintaining user comfort. One example is shown in U.S. Pat. No. 6,581,602 to Kwok, et al. This arrangement shows a cushioned ventilation mask that has fixed flanges, arms and eyelets onto which mounting straps or a harness may be connected. The flanges, arms and eyelets on the mask are not adjustable, however, and therefore can not act to adequately secure the ventilation mask to the face of a wearer while maintaining the highest level of comfort of the wearer.
Another example of a ventilation mask is shown in U.S. Pat. No. 5,647,357. This mask is also cushioned and has several fixed flanges that do not allow for a user to adjust the mask itself while fitting it to their face.
Therefore a need exists for a mask that has adjustability to allow for the proper sealing of the mask against the face of a wearer while maintaining a level of comfort that allows a wearer to use the mask for extended periods of time, for example, while sleeping.